1. Field
Aspects of embodiments according to the present invention relate to an organic light-emitting display device, and more particularly, to a transparent organic light-emitting display device.
2. Description of the Related Art
Applications of organic light-emitting display devices range from personal portable devices, such as MP3 players and mobile phones, to television sets due to having superior characteristics such as wide viewing angles, high contrast ratios, fast response times, and low power consumption.
An organic light-emitting display device has self light-emitting characteristics, and the weight and thickness of the organic light-emitting display device can be reduced since the organic light-emitting display device does not require an additional light source, unlike a liquid crystal display device.
Also, the organic light-emitting display device can be formed to be a transparent display device by having transparent thin film transistors and transparent organic light-emitting devices.
In a transparent display device according to the related art, when the device is in an off-state, an object or an image at a side of the device opposite to the user is viewable to the user through not only organic light-emitting devices but also through patterns of thin film transistors and various wires and through spaces between the patterns of the thin film transistors and various wires. In the above-described transparent display device, the transmittances of the organic light-emitting devices, the thin film transistors, and the wires are not so high, and spaces between the organic light-emitting devices, the thin film transistor, and the wires are very small, and thus, the transmittance of the transparent display device is not high.
Also, an image viewable to the user may be distorted due to the above-described patterns, i.e., the patterns of the organic light-emitting devices, the thin film transistors, and the wires. The reason for this is because gaps between the patterns are only a few nanometers, that is, at a level close to the wavelengths of visible light, and thus, the gaps scatter light passing therethrough.
Furthermore, when an opposite electrode to be commonly deposited on the entire screen is formed with a small thickness in order to improve the transmittance of external light, a voltage drop, i.e., an IR drop, may occur at the opposite electrode, and in particular, as the size of an organic light-emitting display device is increased, the voltage drop may be significant.